The present invention relates to a bucket wheel sluice comprising a sluice wheel which rotates within a housing and which has a plurality of outstanding vanes that glide across and sealingly engage opposed curved walls located between a housing intake and a housing outlet; and is more particularly concerned with an apparatus of the type described wherein a mechanical removal unit is provided for rotation with the bucket wheel, said removal unit having elongated elements which extend generally parallel to the axis of rotation of the bucket wheel and which pass successively through successive pockets of the bucket wheel to remove any entrapped material therein for discharge at the bucket wheel outlet.
Bucket wheel sluices have been suggested heretofore which have plural pockets formed on the periphery of the wheel for the reception of material at a housing inlet, and for transport of such material to a housing outlet. In such arrangements, it is highly desirable to provide a relatively large difference in pressure between the inlet (or intake) and outlet (or discharge) of the bucket wheel sluice. In order to achieve this operating characteristic, the bucket wheel sluice must be provided with a relatively large number of vanes which sealingly engage the housing walls between the housing inlet and outlet, and the necessary seal can be accomplished most advantageously if the pockets which are formed between the sealing vanes have a relatively small profile. If an arrangement of this type is provided, however, and the bucket wheel sluice is to be used for conveying loose material that does not readily flow, a problem arises in that the pockets at the periphery of the sluice do not drain completely empty at the housing discharge.
In an attempt to rectify the foregoing problem, it has been suggested heretofore that a pneumatic removal unit be provided for blasting the pockets free of entrapped material at the discharge side of the housing. The specific arrangements which have been normally employed for this purpose heretofore, however, have been so constructed that it is no longer feasible to maintain a large difference in pressure between the intake and discharge side of the housing. It has been further suggested that the pockets of the bucket wheel surface have a cup-shaped, preferably semi-circular, profile to minimize the entrapment of material within the pockets and to permit such material to drop freely from the pockets at the housing discharge; but even when arrangements of this type are employed it has still been found that when certain materials that do not readily flow are being transported, the material will still not drain from the cup-shaped pockets, or will only partially drain therefrom at the housing outlet.
The principal object of the present invention is, accordingly, to provide a bucket wheel sluice which is so constructed that a relatively large difference in pressure can be readily achieved between the intake and discharge side of the apparatus, and wherein materials, including materials that do not readily flow, will be completely and efficiently removed from the sluice wheel pockets at the discharge side of the housing.